Răspuns:
Explicație pas cu pas:
a) n/5 ≤ 4/5
n = 1; 2; 3; 4
_________
b) 6/n > 6/7
n = 1; 2; 3; 4; 5; 6
_________
c) 1/4 ≤ 1/n < 1/2
1/n < 1/2
n = 3, 4, 5, .....+∞
1/4 ≤ 1/n
n ≤ 4
Solutia n = 3; 4
___________
d) 5/8 < 5/n ≤ 8/4
5/8 < 5/n
n = 1; 2; 3; 4; 5; 6; 7
5/n ≤ 8/4
20 ≤ 8n
5 ≤ 2n
n = 3; 4; 5; 6; 7
Solutia n = 3; 4; 5; 6; 7